Judges will decide once and for all whether airlines in the UK will be allowed to deny passengers compensation for lengthy flight delays caused by technical faults affecting the plane.

EU law states that airlines must pay out up to €600 for delays of more than three hours, but airlines are protected if the delay is caused by extraordinary circumstances that are 'not inherent in the running of an aircraft' - such as industrial action, bird strikes or extreme weather.

Airlines have interpreted this to mean they can deny compensation for delays caused by technical faults with the plane, and some have even gone as far as using blocked toilets, rust or faulty kitchen equipment, according to flight delay lawyers Bott & Co.

Fight: Jet2 has appealed to have a court ruling about flight delays overturned.

But an English court ruled in October that airlines must expect to encounter technical problems during the day-to-day running of aircrafts and should have the procedures in place to deal with them.

The court found in favour of three Jet2 passengers who were denied compensation after their flight from Malaga to Manchester was delayed by 27 hours by a fuel valve fault in 2011.

Jet2 has challenged the decision and the case started in London's Court of Appeal yesterday

The judgement, which could take weeks to be passed, will have a massive bearing on UK airlines who face paying out millions in compensation if Jet2 is unsuccessful in its appeal.

Countries such as Germany and the Netherlands have already ruled that airlines should pay out for delays caused by technical faults.

Kevin Clarke, aviation lawyer at Bott & Co, said: 'It’s ludicrous that if an English, Dutch and German passenger were all on the same flight that was delayed due to a technical reason that only the two from mainland Europe could be certain they could claim with no objections.

'How can this be when all the passengers would be claiming under the same EU law?

'We’ve seen clients who originally approached the airlines for compensation themselves but were told they didn’t have a claim because the delay was caused by an extraordinary circumstance.

'Our experts then looked into the precise nature of the fault and found that excuses such as blocked toilets, faulty microwaves and rust were being passed off as extraordinary circumstances. It’s just not on. We took these cases on and subsequently won against the airline.'

A Jet2 spokesman said: 'As EU legislation on passenger rights currently stands, neither customers nor the airline industry have clarity on the situation. We regret this ambiguity, which has caused so much confusion for travellers.

'This case, which certainly shows that there are no easy answers, could have a significant impact on the entire airline industry. That’s why we are appealing against this point of law and are supporting the ongoing review of EC 261 to make the air travel rules fairer, clearer, and simpler to apply.

'Jet2.com’s focus is always on providing high levels of service at great prices, and we take complaints very seriously. When unprecedented disruptions occur, our priority is to make sure our customers reach their destination as soon as possible.'